Much is known about the anatomy and physiology of accommodation. Our research goal is learning how the retinal stimulus is processed to determine the state of blur and to control the ciliary muscle. Because accommodation is inherently involved with convergence, a successful theory of accommodation will require binocular, three-dimensional experimentation. Toward this end, the SRI eyetracker and optometer were merged into a single, three-dimensional instrument. A binocular system became operational at SRI in December 1975. Another instrument completed this year is a three-dimensional stimulator through which the subject views an arbitrary target. By means of servo-controlled mirrors and a movable lens system, the eye can be stimulated to make horizontal, vertical and accommodation responses independently. In the binocular configuration, two such three-dimensional stimulators are used. We are now able to examine the basic interactions among the saccadic, convergence, and accommodation systems. For instance, with the eyes fixated straight ahead, strong consensual accommodation response has been recorded to a change target distance only (without accompanying convergence). We have also recorded dynamic responses to disparity-driven accommodation with open-loop focus, i.e., without accompanying retinal blur. Simultaneous optometer records show a large degree of accommodation independence in each eye.